Radiator having a reverse flow manifold

ABSTRACT

Disclosed herein is a radiator comprising a heat exchanger that includes a plurality of fluid conduits for carrying a thermal fluid. Each fluid conduit extends along a longitudinal axis between a first end and a second end. At least some of the fluid conduits are laterally offset from each other. The radiator also comprises a direct-flow manifold and, a reverse-flow manifold. The direct flow manifold is for conveying the thermal fluid along a first flow direction between the first ends of the fluid conduits and a first radiator line. The reverse-flow manifold is for conveying the thermal fluid along a second flow direction between the second ends of the fluid conduits and an elbow passageway, and along a third flow direction between the elbow passageway and a second radiator line. The third flow direction is opposite to the second flow direction.

TECHNICAL field

The embodiments disclosed herein relate generally to radiators forheating rooms and other spaces, and, in particular to radiators having aplurality of fluid conduits for carrying a thermal fluid such as water.

INTRODUCTION

The following paragraphs are not an admission that anything discussed inthem is prior art or part of the knowledge of persons skilled in theart.

Radiators are used to heat rooms within buildings. Some heating systemshave boilers that heat water and circulate hot water through theradiators. In these cases, the radiator may have one or more pipes orfluid conduits for carrying the hot water. Fins can be attached to thepipes, which may enhance heating capabilities.

Conventional radiators are generally configured to operate using supplywater at temperatures of at least 140° F., and usually around 180° F. ormore. This poses a problem because recently developed high-efficiencycondensing boilers supply water at much lower temperatures of 128° F. orless. Conventional radiators tend to perform poorly when using this lowtemperature water.

One way of improving performance of conventional radiators is toincrease the operating temperature of the condensing boilers in order tosupply hotter water (e.g. at temperatures of 140° F. to 180° F.). Whilethis can improve performance of the radiator, it significantly decreasesefficiency of the condensing boiler, which can be undesirable.

Accordingly, there is a need for a new or improved radiator, and inparticular, there is a need for a radiator that is capable of operatingwith low temperature water.

SUMMARY

According to some embodiments, there is a radiator comprising a heatexchanger that includes a plurality of fluid conduits for carrying athermal fluid. Each fluid conduit extends along a longitudinal axisbetween a first end and a second end. At least some of the fluidconduits are laterally offset from each other. The radiator alsocomprises a direct-flow manifold and a reverse-flow manifold. The directflow manifold is for conveying the thermal fluid along a first flowdirection between the first ends of the fluid conduits and a firstradiator line. The reverse-flow manifold is for conveying the thermalfluid along a second flow direction between the second ends of the fluidconduits and an elbow passageway, and along a third flow directionbetween the elbow passageway and a second radiator line. The third flowdirection is opposite to the second flow direction.

According to some embodiments, there is a radiator comprising a heatexchanger that includes a plurality of fluid conduits for carrying athermal fluid. Each fluid conduit extends along a longitudinal axisbetween a first end and a second end. At least some of the fluidconduits are vertically offset from each other. The radiator alsocomprises a direct-flow manifold and a reverse-flow manifold. Thedirect-flow manifold is coupled to the first ends of the fluid conduits.The direct-flow manifold has a first fluid passageway that is in fluidcommunication with the fluid conduits and that extends downward forconnection to a first radiator line. The reverse-flow manifold iscoupled to the second ends of the fluid conduits. The reverse-flowmanifold has a second fluid passageway and a third fluid passageway. Thesecond fluid passageway is in fluid communication with the fluidconduits and extends upward. The third fluid passageway is in fluidcommunication with the second fluid passageway and extends downward forconnection to a second radiator line.

According to some embodiments, there is a radiator comprising a heatexchanger that includes a plurality of fluid conduits for carrying athermal fluid. Each fluid conduit extends along a longitudinal axisbetween a first end and a second end. At least some of the fluidconduits are laterally offset from each other. The radiator alsocomprises a direct-flow manifold and a reverse-flow manifold. Thedirect-flow manifold is coupled to the first ends of the fluid conduits.The direct-flow manifold has a first fluid passageway that is in fluidcommunication with the fluid conduits and that extends along a firstlateral direction for connection to a first radiator line. Thereverse-flow manifold is coupled to the second ends of the fluidconduits. The reverse-flow manifold has a second fluid passageway and athird fluid passageway. The second fluid passageway is in fluidcommunication with the fluid conduits and extends along a second lateraldirection that is opposite to the first lateral direction. The thirdfluid passageway is in fluid communication with the second fluidpassageway and extends along a third lateral direction for connection toa second radiator line. The third lateral direction is generallyopposite to the second lateral direction.

The fluid conduits may be arranged in a grid having a plurality ofcolumns and a plurality of rows.

The first fluid passageway of the direct-flow manifold may be centrallyand symmetrically aligned between the columns of the fluid conduits, andthe second fluid passageway of the reverse-flow manifold may becentrally and symmetrically aligned between the columns of the fluidconduits.

At least one of the first and second fluid passageways may have across-sectional area that changes between the rows of the fluidconduits. The change in the cross-sectional area between adjacent rowsof fluid conduits may generally correspond to cross-sectional fluid flowarea of the fluid conduits within each row.

The reverse-flow manifold may have an elbow passageway providing fluidcommunication between the first fluid passageway and the second fluidpassageway.

The heat exchanger may include a plurality of fins arranged along thefluid conduits. Each fin may include a main plate arranged transverse tothe fluid conduits. The main plate may have a plurality of openings forreceiving the fluid conduits therethrough. Each fin may also include aplurality of collars that project outward from the main plate. Eachcollar may circumscribe one of the openings and may provide thermalcontact between the main plate and one of the fluid conduits.

The main plate may have a plurality of indentations.

The main plate may be 5.5-inches long and 2.7-inches wide.

The openings may be arranged in a grid having two columns and threerows. The columns may be spaced apart by about 1.2-inches, and the rowsmay be spaced apart by about 1.8-inches.

The collars may have a depth of about 0.2-inches.

The heat exchanger may be at least about 3-feet long.

The radiator may further comprise an enclosure containing the heatexchanger, the direct-flow manifold, and the reverse-flow manifold. Theenclosure may include a back portion and at least one support bracketfor supporting the heat exchanger on the back portion. The supportbracket may include: an upper bracket portion mounted to the backportion above the heat exchanger; a lower bracket portion mounted to theback portion below the heat exchanger; and a cage removably coupled tothe upper bracket portion and the lower bracket portion for holding theheat exchanger in place. The radiator may also comprise a vibrationisolator between the support bracket and the heat exchanger.

Other aspects and features will become apparent, to those ordinarilyskilled in the art, upon review of the following description of someexemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings included herewith are for illustrating various examples ofarticles, methods, and apparatuses of the present specification. In thedrawings:

FIG. 1 is an exploded perspective view of a radiator according to oneembodiment;

FIG. 2 is a perspective view of the radiator of FIG. 1 with an enclosureand some fins removed for clarity;

FIG. 3 is a partial cross-sectional view of the radiator of FIG. 2 takenalong line 3-3 showing a direct-flow manifold and a reverse-flowmanifold; and

FIG. 4 is a perspective view of a fin of the radiator of FIG. 1.

DETAILED DESCRIPTION

Various apparatuses or processes will be described below to provide anexample of an embodiment of each claimed invention. No embodimentdescribed below limits any claimed invention and any claimed inventionmay cover processes or apparatuses that differ from those describedbelow. The claimed inventions are not limited to apparatuses orprocesses having all of the features of any one apparatus or processdescribed below or to features common to multiple or all of theapparatuses described below. It is possible that an apparatus or processdescribed below is not an embodiment of any claimed invention. Anyinvention disclosed below that is not claimed in this document may bethe subject matter of another protective instrument, for example, acontinuing patent application, and the applicants, inventors or ownersdo not intend to abandon, disclaim or dedicate to the public any suchinvention by its disclosure in this document.

Referring to FIG. 1, there is a radiator 10, which may be used to heat aspace such as a room within a building. In some embodiments, theradiator 10 may be configured to operate with low temperature fluids.For example high-efficiency condensing boilers may output water oranother thermal fluid at a temperature of less than about 140° F., ormore particularly about 128° F. or less. These temperatures are muchlower than water used with conventional boilers and radiators. Based onthe ability to operate at with low temperature fluids, the radiator 10may be referred to as a “low-temperature” radiator.

As shown in FIG. 1, the radiator 10 may include an enclosure 14. Theenclosure 14 may include a back portion 16 and a front portion 18, whichmay also be referred to as a “cover”. The front portion 18 may beremovably secured to the back portion 16.

The radiator 10 includes a heat exchanger 20, which may be containedwithin the enclosure 14. Referring to FIG. 2, the heat exchanger 20includes a plurality of fluid conduits 22 for carrying a thermal fluidsuch as water or glycol. The fluid conduits 22 may be made from a metalsuch as brass or copper, or another thermally conductive material. Aplurality of fins 24 may be arranged along the fluid conduits 22. Thefins 24 may be thermal contact with the fluid conduits 22 for conductingthermal energy therebetween. For example, the fins 24 may be press-fitonto the fluid conduits 22. In some embodiments, the fins 24 may bewelded or brazed on to the fluid conduits 22.

Each fluid conduit 22 extends along a longitudinal axis A between afirst end 26 and a second end 28. As shown, some of the fluid conduits22 are laterally offset from each other along one or more lateraldirections that are generally transverse or perpendicular to thelongitudinal axis A. For example, the fluid conduits 22 may bevertically offset, horizontally offset, or both.

In the illustrated embodiment, the fluid conduits 22 are arranged in agrid. More particularly, the fluid conduits 22 are arranged in a grid oftwo columns and three rows. In other embodiments, there may be adifferent number of columns or rows.

Referring still to FIG. 2, the radiator 10 includes a first manifold 30,and a second manifold 32. Each manifold 30, 32 is coupled to an end 26,28 of the fluid conduits 22. The manifolds 30, 32 may also be referredto as “end caps”. The manifolds 30, 32 may be made from a metal such asbrass, or another suitable material.

As shown, the first manifold 30 may be coupled to a first radiator line34, and the second manifold 32 may be coupled to a second radiator line36. The first radiator line 34 may be a supply line, and the secondradiator line 36 may be a return line. Accordingly, thermal fluid mayflow left to right as shown in FIG. 2.

With reference now to FIG. 3, the first manifold 30 conveys thermalfluid along a first flow direction D1 between the first radiator line 34and the fluid conduits 22. As shown, the first flow direction D1 may bean upward direction. Since thermal fluid flows directly between thefirst radiator line 34 and the fluid conduits 22 along the first flowdirection D1, the first manifold 30 may be referred to as a “direct-flowmanifold”.

In contrast to the first manifold 30, the second manifold 32 conveysthermal fluid along two different directions. In particular, the secondmanifold 32 conveys fluid along a second flow direction D2 between thefluid conduits 22 and a reversing point 38, and along a third flowdirection D3 between the reversing point 38 and the second radiator line36. As shown, the third flow direction D3 may be generally opposite tothe second flow direction D2 (e.g. the second flow direction may beupward, and the third flow direction may be downward). Since thermalfluid flows along two opposing directions, the second manifold 32 may bereferred to as a “reverse-flow manifold”.

As described above, the first manifold 30 may be coupled to the supplyline 34 and the second manifold 32 may be coupled to the return line 36.Accordingly, the first flow direction D1 may be a forward or upwarddirection from the supply line 34 to the fluid conduits 22. Furthermore,the second flow direction D2 may be a forward or upward direction fromthe fluid conduits 22 to the reversing point 38, and the third flowdirection D3 may be a reverse or downward direction from the reversingpoint 38 to the return line 36. In other embodiments, the directions D1,D2 and D3 could be different. For example, if the first manifold 30 werecoupled to the return line and the second manifold 32 were coupled tothe supply line, the thermal fluid would flow in the opposite direction(i.e. right to left) and the directions D1, D2 and D3 would be oppositeto that described above.

In some embodiments, the first and second flow directions D1 and D2 maybe generally similar to one another. For example, in the illustratedembodiment, the first and second flow directions D1 and D2 are parallelto each other and point in the same general direction. In otherembodiments, the first and second flow directions D1 and D2 could bedifferent and might be angled with respect to each other.

Referring still to FIG. 3, the structure of the direct-flow manifold 30and the reverse-flow manifold 32 will now be described in greaterdetail.

The direct-flow manifold 30 is coupled to the first ends 26 of the fluidconduits 22. For example, the direct-flow manifold 30 may have aplurality of fluid couplings coupled to the fluid conduits 22 (e.g.inlet couplings 41A, 41B, 41C).

The direct-flow manifold 30 has a first fluid passageway 40 in fluidcommunication with the fluid conduits 22 (e.g. via the couplings 41A,41B, 41C). The first fluid passageway 40 extends along a first lateraldirection for connection to the first radiator line 34. The firstlateral direction may be generally parallel to the first flow directionD1 and may extend downward from the fluid conduits 22 to the supply line34.

The reverse-flow manifold 32 is coupled to the second ends 28 of thefluid conduits 22. For example, the reverse-flow manifold 32 may have aplurality of fluid couplings coupled to the fluid conduits 22 (e.g.outlet couplings 43A, 43B, 43C).

The reverse-flow manifold 32 has two fluid passageways, namely, a secondfluid passageway 42 and a third fluid passageway 44. The second andthird fluid passageways may extend in generally opposite directions. Anelbow passageway 46 may provide fluid communication between the secondfluid passageway 42 and the third fluid passageway 44. The elbowpassageway 46 may define the reversing point 38.

As shown, the second fluid passageway 42 is in fluid communication withthe fluid conduits 22 and extends along a second lateral direction,which may be generally similar to the second flow direction D2 and mayextend upward from the fluid conduits 22. The third fluid passageway 44is in fluid communication with the second fluid passageway 42 andextends along a third lateral direction for connection to the secondradiator line 36. The third lateral direction may be generally similarto the third flow direction D3 and may extend downward for connection tothe second radiator line 36.

As shown, the first, second, and third lateral directions of the fluidpassageways 40, 42, 44 are generally transverse to the longitudinal axisA. For example, as shown, the first, second, and third lateraldirections may be generally perpendicular to the longitudinal axis A.Alternatively, the first, second, and third lateral directions could beat oblique angles to the longitudinal axis A.

Using the direct-flow manifold 30 and the reverse-flow manifold 32 mightenhance thermal performance of the radiator 10. This can be particularlybeneficial when using low temperature water of 128° F. or less (e.g. assupplied by a high-efficiency condensing boiler). One possible reasonfor enhanced thermal performance is that that each row of fluid conduits22 might have a more uniform fluid flow distribution in comparison toconventional radiators that have direct-flow manifolds on each end ofthe fluid conduits 22. Having a more evenly distributed flow fluidwithin the fluid conduits 22 might provide a more uniform temperaturegradient across the heat exchanger 20, and thus, might enhance thermalperformance.

The even flow distribution might be due to reducing or equalizing flowrestrictions through the fluid conduits 22. For example, with referenceto FIG. 3, the first, second, and third fluid conduits 22A, 22B, 22Cmight each receive a portion of total fluid flow. Fluid flow through thefirst fluid conduit 22A might be associated with a first inlet flowrestriction through the first inlet coupling 41A, and a first outletflow restriction through the first outlet coupling 43A. Furthermore,fluid flow through the second fluid conduit 22B might be associated witha second inlet flow restriction through the second inlet coupling 41B,and a second outlet flow restriction through the second outlet coupling43B. Finally, fluid flow through the third fluid conduit 22C might beassociated with a third inlet flow restriction through the third inletcoupling 41C, and a third outlet flow restriction through the thirdoutlet coupling 43C.

The reverse-flow manifold 32 might help balance or match flowrestrictions with the direct-flow manifold 30 in reverse order. Forexample, the combined flow restrictions through the first inlet andoutlet couplings 41A, 43A might be similar to that of the second inletand outlet couplings 41B, 43B, and similar to that of the third inletand outlet couplings 41C, 43C. It is believed that matching the flowrestrictions through the fluid conduits 22 in this way might helpequalize pressure drop through each fluid conduit 22, and thus,distribute fluid flow more uniformly, and possibly enhance thermalperformance.

In contrast, if two direct-flow manifolds were used, the flowrestrictions through the first inlet and outlet couplings 41A, 43A mightbe different to that of the second inlet and outlet couplings 41B, 43B,and different to that of the third inlet and outlet couplings 41C, 43C.This might result in uneven flow through the fluid conduits 22, whichmight decrease thermal performance.

Referring again to FIGS. 2 and 3, the manifolds 30, 32 may besymmetrically aligned with the columns of fluid conduits 22 (e.g. alongthe cross-sectional plane defined by the line 3-3). For example, thefirst fluid passageway 40 of the direct-flow manifold 30 may becentrally and symmetrically aligned between the two columns of fluidconduits 22. Furthermore, the second fluid passageway 42 of thereverse-flow manifold 32 may be centrally and symmetrically alignedbetween the at least two columns of fluid conduits. Having the manifolds30, 32 symmetrically aligned with the fluid conduits 22 in this waymight help maintain uniform fluid flow through each fluid conduit withina particular row.

In some embodiments, the fluid passageways 40, 42 of the manifolds 30,32 might have a cross-sectional area that changes between rows of fluidconduits 22. For example, as shown FIG. 3, the fluid passageway 40 ofthe direct-flow manifold 30 might have a cross-sectional area thatdecreases from a proximal row of fluid conduits (e.g. the first fluidconduits 22A) to a distal row of fluid conduits (e.g. the third fluidconduits 22C).

In some embodiments, the change in cross-sectional area of the fluidpassageway between adjacent rows of fluid conduits 22 may correspond tocross-sectional fluid flow area of those fluid conduits 22. For example,the decrease in cross-sectional area of the fluid passageway 40 betweenthe first fluid conduit 22A and the second fluid conduit 22B maycorrespond to the cross-sectional area of the two first fluid conduits22A. Similarly, the decrease in cross-sectional area of the first fluidpassageway 40 between the second fluid conduit 22B and the third fluidconduit 22C may correspond to cross-sectional area of the two secondfluid conduits 22B. Configuring the cross-sectional areas in this waymight help maintain a fluid flow velocity that is generally similarthrough the fluid passageways 40, 42 as well as the fluid conduits 22,and thus, help maintain a more uniform fluid flow through the fluidconduits 22.

As described above, the radiator 10 may include a plurality of fins 24.Referring to FIGS. 2 and 4, each fin 24 may include a main plate 50arranged transverse to the fluid conduits 22. The fin 24 may have agenerally rectangular shape. For example, as shown, the main plate 50may have a length L of about 5.5-inches, and a width W of about2.7-inches. In other embodiments, the fin 24 could have other shapes andsizes.

The main plate 50 has a plurality of openings 52 for receiving the fluidconduits 22 therethrough. As shown, the openings 52 may be arranged in agrid. For example, there are two columns and three rows of openings 52in the illustrated embodiment. The columns may be spaced apart by acolumn spacing 70 (e.g. of about 1.2-inches), and the rows may be spacedapart by a row spacing 72 (e.g. of about 1.8-inches). Furthermore, thefirst and last columns may be spaced from the edge of the fin 24 byabout half of the column spacing 70 (e.g. about 0.6-inches), and thefirst and last rows may be spaced from the edge of the fin 24 by abouthalf of the row spacing 72 (e.g. about 0.9-inches). In otherembodiments, there could be a different number of openings, and theopenings could have different spacing and geometric arrangements.

Each fin 24 may also include a plurality of collars 54 that projectoutwardly from the main plate 50. Each collar 54 may circumscribe ordefine one of the openings 52. The collars 54 may provide thermalcontact between the main plate 50 and the fluid conduits 22. The collarsmay have a collar depth 55 (e.g. of about 0.2-inches).

In some embodiments, the main plate 50 may have a plurality ofindentations 56. The indentations 56 may be formed as elongate,wave-like ripples in the main plate 50. The indentations 56 may increasethe surface area of the fin 24, which may enhance thermal performance.

Referring again to FIG. 1, the enclosure 14 may contain the heatexchanger 20, the direct-flow manifold 30, and the reverse-flow manifold32. Furthermore, the enclosure 14 may include one or more supportbrackets 80 for supporting the heat exchanger 20. More particularly, inthe illustrated embodiment, there are two support brackets 80 forsupporting the heat exchanger 20 on the back portion 16 of the enclosure14. Each support bracket 80 may include an upper bracket portion 82mounted to the back portion 16 above the heat exchanger 20, and a lowerbracket portion 84 mounted to the back portion 16 below the heatexchanger 20.

The support bracket 80 may also include a grate or cage 86 that isremovably coupled to the bracket portions 82, 84 for holding the heatexchanger 20 in place. The cage 86 may be formed from a wire that ishooked into a slot on the lower bracket portion 84. The wire cage 86 mayalso have ends 88 that extend through apertures in the upper bracketportion 82. The cage 86 may be removed by squeezing the middle of thewire cage 86 together so as to deflect the cage 86 inwards and pull thewire ends 88 through the apertures in the upper bracket portion 82. Thebottom of the cage 86 can then be unhooked from the lower bracketportion 84 to remove the cage 86. After removal, the heat exchanger 20can be disconnected from the radiator lines 34, 36 and then removed fromthe enclosure 14. The heat exchanger 20 can be installed by reversingthis process.

In some embodiments, the radiator 10 may also include a vibrationisolator 90 between the support bracket 80 and the heat exchanger 20.For example, the vibration isolator 90 may be a silicone pad that ispressed between the wire cage 86 and the fins 24 of the heat exchanger20. This may help reduce noise such as rattling.

The radiator 10 may be made in a variety of lengths. For example, in theillustrated example, the radiator 10 may be approximately 3-feet long.This may allow attachment of the radiator 10 to a supply line 34 and areturn line 36 that are approximately 3-feet apart. In otherembodiments, the radiator 10 may be longer or shorter. For exemplarypurposes only, the radiator 10 may be manufactured in standard lengthsranging from 2-feet to 10-feet (e.g. in one foot increments). Having avariety of lengths can be particularly useful when the radiator isdesigned for drop-in replacement for existing radiators that are beingreplaced.

While the above description provides examples of one or more apparatus,methods, or systems, it will be appreciated that other apparatus,methods, or systems may be within the scope of the claims as interpretedby one of skill in the art.

1. A radiator comprising: a) a heat exchanger including a plurality offluid conduits for carrying a thermal fluid, each fluid conduitextending along a longitudinal axis between a first end and a secondend, at least some of the fluid conduits being laterally offset fromeach other; b) a direct-flow manifold for conveying the thermal fluidalong a first flow direction between the first ends of the fluidconduits and a first radiator line; c) a reverse-flow manifold forconveying the thermal fluid along: i) a second flow direction betweenthe second ends of the fluid conduits and an elbow passageway; and ii) athird flow direction between the elbow passageway and a second radiatorline, the third flow direction being opposite to the second flowdirection.
 2. A radiator comprising: a) a heat exchanger including aplurality of fluid conduits for carrying a thermal fluid, each fluidconduit extending along a longitudinal axis between a first end and asecond end, at least some of the fluid conduits being vertically offsetfrom each other; b) a direct-flow manifold coupled to the first ends ofthe fluid conduits, the direct-flow manifold having a first fluidpassageway that is in fluid communication with the fluid conduits andthat extends downward for connection to a first radiator line; and c) areverse-flow manifold coupled to the second ends of the fluid conduits,the reverse-flow manifold having: i) a second fluid passageway that isin fluid communication with the fluid conduits and that extends upward;and ii) a third fluid passageway that is in fluid communication with thesecond fluid passageway and that extends downward for connection to asecond radiator line.
 3. A radiator comprising: a) a heat exchangerincluding a plurality of fluid conduits for carrying a thermal fluid,each fluid conduit extending along a longitudinal axis between a firstend and a second end, at least some of the fluid conduits beinglaterally offset from each other; b) a direct-flow manifold coupled tothe first ends of the fluid conduits, the direct-flow manifold having afirst fluid passageway that is in fluid communication with the fluidconduits and that extends along a first lateral direction for connectionto a first radiator line; and c) a reverse-flow manifold coupled to thesecond ends of the fluid conduits, the reverse-flow manifold having: i)a second fluid passageway that is in fluid communication with the fluidconduits and that extends along a second lateral direction opposite tothe first lateral direction; and a third fluid passageway that is influid communication with the second fluid passageway and that extendsalong a third lateral direction for connection to a second radiatorline, the third lateral direction being generally opposite to the secondlateral direction.
 4. The radiator of claim 3, wherein the fluidconduits are arranged in a grid having a plurality of columns and aplurality of rows.
 5. The radiator of claim 4, wherein a) the firstfluid passageway of the direct-flow manifold is centrally andsymmetrically aligned between the columns of the fluid conduits; and b)the second fluid passageway of the reverse-flow manifold is centrallyand symmetrically aligned between the columns of the fluid conduits. 6.The radiator of claim 5, wherein at least one of the first and secondfluid passageways has a cross-sectional area that changes between therows of the fluid conduits.
 7. The radiator of claim 6, wherein thechange in the cross-sectional area between adjacent rows of fluidconduits generally corresponds to cross-sectional fluid flow area of thefluid conduits within each row.
 8. The radiator of claim 3, wherein thereverse-flow manifold has an elbow passageway providing fluidcommunication between the first fluid passageway and the second fluidpassageway.
 9. The radiator of claim 3, wherein the heat exchangerincludes a plurality of fins arranged along the fluid conduits.
 10. Theradiator of claim 9, wherein each fin includes: a) a main plate arrangedtransverse to the fluid conduits, the main plate having a plurality ofopenings for receiving the fluid conduits therethrough; b) a pluralityof collars that project outward from the main plate, each collarcircumscribing one of the openings and providing thermal contact betweenthe main plate and one of the fluid conduits.
 11. The radiator of claim10, wherein the main plate has a plurality of indentations.
 12. Theradiator of claim 10, wherein the main plate is 5.5-inches long and2.7-inches wide.
 13. The radiator of claim 10, wherein the openings arearranged in a grid having two columns and three rows, the columns beingspaced apart by about 1.2-inches, and the rows being spaced apart byabout 1.8-inches.
 14. The radiator of claim 10, wherein the collars havea depth of about 0.2-inches.
 15. The radiator of claim 3, wherein theheat exchanger is at least about 3-feet long.
 16. The radiator of claim3, further comprising an enclosure containing the heat exchanger, thedirect-flow manifold, and the reverse-flow manifold.
 17. The radiator ofclaim 16, wherein the enclosure includes a back portion and at least onesupport bracket for supporting the heat exchanger on the back portion.18. The radiator of claim 17, wherein the support bracket includes: a)an upper bracket portion mounted to the back portion above the heatexchanger; b) a lower bracket portion mounted to the back portion belowthe heat exchanger; and c) a cage removably coupled to the upper bracketportion and the lower bracket portion for holding the heat exchanger inplace.
 19. The radiator of claim 17, further comprising a vibrationisolator between the support bracket and the heat exchanger.